Sonny and his sister Maddie, also born with only two legs, were recently adopted after being abandoned. Kelley Stewart, a Muncie resident who owns a dog care business, adopted Sonny, and Maddie found a home with Jalen Duncan, also of Muncie, after Stewart posted on Facebook about the dogs, according to The Star Press.

The two Chihuahuas learned how to get around by hopping in a manner similar to kangaroos, but would still take the occasional tumble. Stewart worried for her dog's welfare and was saving up to buy a wheelchair for him.

"He's OK on grass now, but I worry about him hurting himself when he's out on concrete and such," Stewart told The Star Pressat the time.

The wheels scared Sonny at first, Stewart says, but the dog's a fast learner. Video taken on Sonny's third day using the wheels shows him wheeling at top speed and sometimes unintentionally going in circles.

"He's still got some learning to do on the maneuvering," Stewart said.